Hydraulic propulsion of vehicles



' Oct. 16, 1934.

E E. ADAMS 1,977,033

HYDRAULIC PROPULSION OF VEHICLES Filed Dec. 13, 1930 7 Sheets-Sheet 1 IWVl WfOr:

Earl J Adams.

E. E. ADAMS Oct. 16, 1934..

HYDRAULIC PROPULSION OF VEHICLES Filed Dec. l3, 1930 7 Sheets-Sheet 2 O v M Oct. 16, 1934. E. E. ADAMS HYDRAULIC PROPULSION OF VEHICLES Filed Dec. 13, 1930 7 Sheets-Sheet 3 105 I n venior:

EarZE. Adams Oct. 16, 1934. E. ADAMS 1,977,033

HYDRAULIC PROPULSION OF VEHICLES Filed Dec. 13, 1950 7 Sheets-Sheet 4 J1 TI'Z'QJZ 47 [/1 l l/ [A I I l/l/ ll/I/l/l/ [I /f Ill/ll Ear/E.A Jam 8.

Jury.

0ct. 16,1934. E. E. ADAMS 1,917,033

HYDRAULIC PROPULSION OF VEHICLES Filed Dec. 13, 1930 7 Sheets- Sheet 5 F jig .22.

:55! 21? Znz/Pnfafl: 126 -1 :1 t L: I 107i 1 Adkins i m cl 5 i I Oct. 16, 1934. E, ADAM 1,977,033

HYDRAULI C PROPULS ION VEHICLE S Filed 1930 7 Sheets-Sheet 6 CI 97 .26. 96 z 1153 f u J K I 4 9.; I? 96 M I I J Ilia"; I x

fizz/anion EarlE Adams.

Patented a. 16, 1934 1,977,033

UNITED STATES PATENT OFFICE 1,977,033 HYDRAULIC PROPULSION 0F VEHICLES Earl E. Adams, Los Angeles, Calif. Application December 13, 1930, Serial No. 502,097 6 Claims. (01. 53)

This invention relates to a hydraulic drive for to effect Various changes of speed by oscillation vehicles of the type embodying a liquid circulatof a hand lever in a rectilinear path of travel and ing system including a power actuated pump, a whereby increases of speed from zero to maxiliquid impelled driving unit on two or more of mum is effected by advancing the lever step by B the vehicle driving wheels, and liquid conductors step in a forward straight line direction and 60 leading to and from each of the driving units reduction of speeds elfected by retrograde step and communicating with said pump through a by step movement of the operating lever. control mechanism. With the foregoing objects in view, together An object of the invention is to provide a hywith such other objects and advantages as may 10 draulic drive for vehicles of the above character subsequently appear, the invention resides in the in which control of the operation of the vehicle parts and in the combination, construction and may be effected in the manner now generally arrangement of parts hereinafter describedeand practiced, that is through the medium of a foot claimed and illustrated by Way Of example in the operated clutch lever, a foot operated brake lever, accompanying drawings, in which:

16 and a hand operated change speed or transmis- Figure 1 is a plan view of the chassis and runsion control lever. ning gear of a motor vehicle showing the inven- Another object is to provide a means in a hytion as applied; draulic vehicle drive which will afford a gear i u e 2 is a View in vertical section of the ratio between the driving and driven elements pump with its as a d control valv s;

20 from zero to one-to-one or direct drive and in Figure 3 is a view in section and elevation as which power can be applied to the driving eleseen o'n'the line 3-3 of Figure 2 in the direction ments continuously while a change of speed is indicated by the a being made and which is adapted to automati- Figure 4 is a plan View of the pump with parts cally effect change in the gear ratio according broken away showing portions in section as seen :5 to varying road conditions; that is to at times on the line 44 of Figure 3; effect a gear ratio reduction when the vehicle is Figure 5 is a detail in cross section as seen on upwardly traversing a grade and to increase the the line 5-5 of Figure 3 with parts shown in elegear ratio when the vehicle is downwardly travvation; ersing a grade. Figure 6 is a projected circumferential section :0 Another object is to provide a hydraulic vehicle as seen on the dotted line indicated at 6 in Figdrive which is particularly applicable for use in ure 3; the propulsion of each of the wheels of a four- Figure 7 is a view in vertical section of one of wheel vehicle thus serving both as a front and the control valves as seen approximately on the rear wheel drive in propelling the vehicle and line 7-7 of Figure 2 with the valve removed;

; also serve to efiect a braking action on each of Figure 8 is a view in horizontal section and plan the four wheels of the vehicle in retarding and with parts broken away as seen on the line 8-8 stopping same. of Figure 7;

Another object is to provide a hydraulic trans- Figure 9 is a view in horizontal section as seen mission pump and associated wheel driving units on the line 9-9 of Figure 7;

0 which are o ple construction and are so Figure 10 is a view in section and elevation as formed as to be highly efficient in operation. seen on the line 10-10 of Figure 8;

Another Object is to P d a Control m ch- Figure 11 is aview in vertical section of another anism in a hydraulic vehicle drive including a control valve as seen on the line 11-11 of Figseries of valves for directing and controlling the ure 4 showing th v lv as d ta h d;

5 flow f q d from a p to and from s ve a Figure 12 is a view in horizontal section as seen driving units whereby the latter may be actun the line 12-42 of Figure 11; ated t0 IBVOIVG collectively in either direction, 01 Figure 13 is a iew in horizontal section as seen their rotation in either direction be retarded or on the line 13-13 of Figure 11; stopped, or whereby the pump may be caused to Figure 14 is a view in vertical section and eleidle and be rendered neutral relatively to the vation as seen on the line 14-14 of Figure 11;

driving units, and which also includes manually Figure 15 is a view in vertical section of one of operated selective means for effecting various the wheel driving units;

positioning of said valves. Figure 1611s a view in elevation as seen in the di- A further object is to provide a speed control rection indicated by the arrow 16 of Figure 15 with mechanism for motor vehicles which is adapted parts broken away; i

Figure 17 is a diagram illustrating an annular section of the wheel driving unit taken on the broken line 17 of Figure 15 as projected on a plane;

Figure 18 is a view in elevation of a pair of foot controlled valves as seen in the direction indicated by the arrow 18 in Figure 1;

Figure 19 is a view in horizontal section taken on the line l919 of Figure 18;

Figure 20 is a view in end elevation as seen in the direction indicated by the arrow 20 in Figure 18;

Figure 21 is a view in end elevation as seen in the direction indicated by the arrow 21 in Figure 18;

Figure 22 is a diagrammatic plan view of the pump and the associated manually operated change speed control mechanism;

Figure 23 is a plan view with parts broken away illustrating the change speed control mechanism showing the parts in the neutral position;

Figure 24 is a fragmentary plan view of the control mechanism showing the parts as disposed in second speed position;

Figure 25 is a view similar to Figure 24 showing the parts as disposed in the third speed position and showing in dotted lines the parts as disposed in the fourth speed position;

Figure 26 is a view in elevation of the change speed operating lever and its connections, with parts broken away;

Figure 27 is a detail in section taken on the line 27-2'7 of Figure 23.

Figure 28 is a diagram showing the parts as disposed in a neutral position.

Figure 29 is a diagram showing the parts as disposed in the first or low position;

Figure 30 is a diagram showing the parts as disposed in a second speed position;

Figure 31 is a diagram showing the parts as disposed in a third speed position;

Figure 32 is a detail in section taken on the line 32-32 of Figure 1, showing the filler tube and shock absorber.

Figure 33 is a diagram illustrating the parts as disposed in a fourth speed position;

Figure 34 is a diagram illustrating the parts as disposed in the reversed position;

Figure 35 is a view in diagram illustrating the parts as disposed in a semi-automatic third and fourth position;

Figure 36 is a view in diagram illustrating the operation of the brake control valves with th valves disposed in the braking position.

Figure 37 is a view in diagram illustrating the clutch control valve in the release position.

Referring to the drawings more specifically, A indicates generally an automobile frame carried on the front and rear axles B and C in a conventional manner. The front axle B is equipped with dirigible front wheels D and E adapted to be steered in a customary manner, not necessary to be here shown. The rear axle C carries the rear vehicle wheels F and G which are revolubly supported on the axle C. The wheels D, E, F, and G may be revolubly supported on their respective axles in any desired manner; a suitable mounting for the wheels being shown by way of example in Figure 15, which will be lat-er described.

In carrying out the present invention, each of the wheels D, E, F, and G is equipped with an hydraulically actuated driving unit H as particularly shown in Figures 15 and 16. This driving unit embodies a rotor I having a tubular cylindrical sleeve portion 40 which encompasses a spindle 41 carried by the axle and on the inner end of which sleeve portion is formed an outwardly projecting flange 42 constituting the rotor body and which is of uniform thickness throughout and has its outer periphery extending concentric with the axis of the spindle 41. Keyed on the sleeve 40 of the rotor is the hub 43 of the vehicle wheel and interposed between the sleeve and the wheel spindle and between the rotor and the wheel spindle are antifriction bearings 44 and 45. The hub 43 is formed with a flange 46 to which is attached the wheel structure 47 in a usual manner. The rotor I is enclosed in a housing J embodying an annular wall portion 48 which encircles the rotor body 42 in slidable contact therewith and which annular portion is formed on a side wall 49 extending over the inner end of the rotor body 42 and is ,afiixed to the spindle 41 as by means of bolts 50 whereby the housing J is held against rotation on the vehicle axle. The housing also includes an annular front wall 51 which encircles the sleeve 40 rearward of the hub flange 46 and is secured by bolts 52 or other suitable fastenings to the housing member 48.

In carrying out the present invention, the rotor head 42 is formed with a plurality of transverse radially extending slots 53 in each of which is mounted a blade 54 the side faces of which slidably contact the walls of the slot 53 and the outer ends of which slidably contact the inner periphery of the annular wall 48 of the housing J and the inner ends of which slidably contact the bottom wall of the slot; each of the blades thus being confined against radial movement relatively to the motor but are shiftable transversely of the latter whereby portions of the side faces thereof may be projected from either side of the rotor head into spaces provided in the walls 49 and 51 of the rotor housing; the wall 49 being formed on its inner face with an arcuate channel 55 of rectangular cross section arranged to be traversed by the blades and which constitutes a chamber for containing an operating liquid whereby actuation and control of the rotor is effected. The blades 54 are designed to be successively advanced into the channel 55 as the rotor revolves and after traversing the channel to be retracted and for which purpose the wall 51 is formed with an arcuate cam groove 56 having a bottom wall formed with end inclines 57 and 58 merging at their ends into a wall portion 59 arranged to slidably contact the outer face of the rotor head at the portion of the housing J opposite the channel 55 as shown in Figure 17. The end portions of the bottom wall of the channel 55 are inclined as indicated at 60 and 61 and are arranged to extend parallel with the inclines 5'7 and 58, respectively. The blades 54 are of such transverse length that their end edges will slidably contact the contiguous portions of the housing throughout their path of travel.

The blades 54 are spaced a distance apart equal to the length of the bottom wall of the cam groove, so that fluid pressure will be relieved from a blade as it advances over the inclines at the ends of the groove.

The housing wall 49 is formed with openings 62 and 63 communicating with the ends of the channel 55 and extending along the incl ned bottom wall 60 and 61 of the latter with which openings communicate tubes 64 and 65 formed integral with the wall 49 and extending diagonally therefrom and which tubes afford connectionswlth be later described.

The blades 54 when disposed out of the channel 55 will project into the channel'5'6 in which a partial vacuum is maintained on rotation of the rotor, and as a means for permittingihe evacuating of any liqud as may accumulate in the channel 56 in advance of the projected portion of a blade traversing the latter, j'clucts 66 and 67 are provided to afford communications between the end portions of the channel '56 and the contiguous end portions of the channel 55, and arranged in the ducts 66 and 67 are check valves 68 and 69 which open toward the channel 55 and are normally closed toward the channel 56 to prevent fluid under pressure from passing from the channel 55 through the ducts to the channel 56 yet permit fluid to be directed from the channel 56 to the channel 55.

Mounted on the motor vehicle frame A in a conventional manner, is a motor K of any suitable character here shown as comprising an internal combustion engine, and operatively connected to the drive shaft 70 of the motor is a pump L which includes a rotor 71 aflixed to the drive shaft 70 as shown in Figure 2 and also embod es a housing including an annular wall portion 72 and end walls 73 and 74. The rotor 71 is formed so that its outer periphery slidably contacts the inner periphery of the housing portion 72 and its opposite side faces to slidably contact the contiguous faces of the housing end walls 73 and '74. The housing wall portions '72 and 73 are here shown as formed integral and the wall portion 7% is dezachably connected thereto as by means of bolts 75 or other suitable fastenings. t In carrying out the present invention, the wall portion 73 of the pump housing is formed with a pair of spaced arcuate channels 76 and 77 extending concentric with the axis of the shaft 70 and each of the grooves '76 and 77 is adapted to be traversed by a plurality of blades 78 and 79 carried by the rotor '71 and arranged to be projected laterally therefrom into the channels as the rotor revolves. The blades 78 and '79 are carried in transverse slots 80 and 81 formed in the rotor 71 and are of such length that their opposite ends will traverse contiguous faces of the housing Walls 73 and 74 in such manner that the blades will be shifted transversely to project one end portion thereof into the channels 76 and 77 as the blades are disposed opposite said channels and also be shifted so that the opposite end portions thereof will be extended from the opposite side of the rotor when the blades have passed out of the channels 76 and 77 and then being disposed in arcuate channels 82 and 83 formed on the housing side wall 74. The channels 82 and 83 are arcuate and extend concentric with the axis of the shaft 70 and are so positioned in such circumferential relation thereto and to the channels 76 and 77 that after the rotor 71 revolves the blades 78 and 79 will traverse the channels 76 and 77 throughout one-half each revolution of the rotor and will traverse the channels 82 and 83 throughout the other half of the revolution of the rotor; the blades being thus alternately projected from one side of the rotor to the other; the bottom walls of the grooves 76, 77. 82, and 83 being inclined at their end portions which latter overlap so that the blades will readily ride in and out of the grooves as illustrated for example in Figure 6.

Formed on the pump housing is a pair of valve casings M and N in which are mounted oscillatory valves 0 and P; the valve 0 serving to control the'flo'w of liquid to and from the grooves 76 and 77 and the valve P servingto control the flow of liquid to and from grooves 82 and 83. The valve casing M is formed with a pair of circumferentially spaced ports a and b which communi' cats with the end portions of the groove 76 and is also formed with circumferentially spaced ports c and d which communicate with the end portions of the groove 77 and in like manner the valve casing N is formed with circumferentially aligned ports e and f communicating with the end portions of the channel 82 and with aligned ports a and h which communicate with the end portions of the groove 83. The ports 0 and d are arranged on a plane above the ports a and b and the ports 9' and h are located on a plane below the ports e and f. The valve casing M is also formed with a pair of ports 2' and 7' aligned with ports a and b and a pair of ports is and Z aligned with the ports c and d. In like manner valve casing N is formed with a pair of ports m and n aligned with the ports e and f and also has a pair of ports 0 and p aligned with ports g and it.

As illustrated diagrammatically in Figure 28 et seq., the ports 2', k, m, and o communicate with a conduit 85, and the ports 7', Z, n, and p communicate with a conduit 86; the conduits 85 and 86 communicating with a pair of circumferentially spaced ports 87 and 88 opening to a cylindrical chamber 89 in a housing 90 containing a foot operated valve Q constituting the equivalent cf a clutch element and which valve includes a pair of passages q and r arranged on opposite sides'of a partition 91 as particularly shown in Figure 19. The passages q and r normally afford a communication between the pair of ports 87 and 88 and a pair of ports 92 and 93 leading to a cylindrical chamber 94 in the housing 90 containing a foot operated valve R constituting the equivalent of a brake.

The valve R is formed with a pair of passages s and t normally registering with the pcrts 92 and 93. The passage s affords a communication between the port 92 and a pair of conduits 95; also with a pair of conduits 96, which conduits 95 and 96 lead to and communicate with the tubes 64 of each of the driving units H. The passage t normally affords a communication between the port 93 and two pairs of conduits 97 and 98 communieating with the tubes 65 of the driving units H. The passage t is formed with an enlarged end portion it which is adapted to effect a communi cation between the ports 92 and 93 on positioning of the valve R as shown in Figure 37.

The control valve 0, particularly shown in Figures 11, 12, 13, and 14, embodies a cylindrical shell 99 across which extends a pair of separated passages 100 and 101; passage 100 affording a means for controlling communication between the ports a and i and the passage 101 affording a means for controlling communication between the ports 0 and k.

The cylindrical shell 99 is formed with openings 102, 103, and 104 arranged in circumferential alignment with the ends of the passage 100 to afford communication between the interior of the valve and the ports a. b, and 7' at various positions of the valve, and being also formed with openings 105, 106, and 107 circumfe entially aligned with the passage 101 to effect communication between the interior of the valve and the ports 0, d, and Z on disposing the valve in various positions.

Control valve P includes a cylindrical shell 108 across which extends a pair of spaced passages 109 and 110; passage 109 being adapted to control communication between the ports e and m and the passage 110 being adapted to control communication between the ports 9 and 0. The shell 108 is formed with openings 111, 112, 113, and 114 arranged in circumferential alignment with the passage 109 which are adapted to afford a communication between the interior of the valve and the ports e, f, m, and n, according to various positions of the valve, and the shell is also formed with a series of openings 115, 116, and 117 arranged in circumferential alignment with the passage 110 and adapted to effect communication between the interior of the valve and the ports 9, h, and 30, according to the position of the valve.

The valve P is also formed with a passage 118 which is adapted to eifect communication between the ports e and n on proper positioning of the valve.

The valves 0 and P are employed in effecting change of speed of the vehicle, that is in effecting different gear ratios of first, second, third, and fourth speeds as well as for placing the hydraulic propulsion system in neutral; the valve P also being employed in effecting and controlling the reverse movement of the vehicle. The valve Q serves to place the fluid transmission in and out of operative communication between the pump and the driving units irrespective of the control valves 0 and P and the valve R is employed to effect retardation and stopping of the movement of the vehicle.

The means for effecting operation of the valves 0 and P is illustrated in Figures 22 to 27, inclusive, and embodies a hand operated lever 120 pivoted at 121 for oscillatory movement in a straight path of travel, together with means actuated by the lever according to movement of the latter to and from several positions to effectuate the desired positioning of the valves, which includes a pair of spaced parallel reciprocal slide bars 122 and 123 mounted in a guide-way 124. The slide bar 122 connects at one end through a link 125 with an arm 126 on a shaft 127 to which the valve 0 is attached, and one end of the slide bar 123 is connected by a link 128 to one end of a rocker arm 129, the opposite end of which connects to a link 130 leading to an arm 131 on a shaft 132 to which the valve P is attached. The connections between the slide bars 122 and 123 and the arms of their respective valves, are arranged on opposite ends of said slide bars as shown in Figure 23.

Formed in the guide-way 124 and extending between the slide bars 122 and 123 in spaced relation thereto, is a rib 133 which constitutes a fixed cam and extending astride of said rib is a yoke 134 carried on a sleeve 135 telescoped on the lower end of the hand lever 120 as shown in Figure 26 and which is thus adapted to be shifted longitudinally of the rib 133 on oscillation of the lever 120. Slidably supported in the yoke 134 is a pair of slide blocks 136 and 137 arranged on opposite sides of the rib 133 and which slide blocks are adapted to be shifted as the yoke 134 is moved longitudinally of the rib 133 by manipulation of the lever 120 to alternately eifect engagement with the slide bars 122 and 123; the bar 122 being formed with a pair of spaced sockets 138 and 139 arranged to be successively engaged by the block 136 and the slide bar 123 being formed with sockets 140 and 141 arranged to be engaged by the block 137.

The hand lever 120 carries a slide block 171 normally disposed in a slot 172 in a hollow standard 173 on which the lever is mounted, which block co-acts with the ends of the slot to limit movement of the lever. A push rod 174 connects with the block whereby the latter may be depressed out of the slot to permit retrograde movement of the lever past its neutral. position.

The parts are so relatively arranged and the cam rib 133 so formed that when the hand lever 120 is disposed in its neutral position as shown in Figure 23, the block 137 will be engaged with the socket 140 on the slide bar 123 while the block 136 will be disposed out of connection with the slide bar 122, and the rib 133 is formed with inclined portions 142, 143, and 144 arranged so that as the yoke traverses theseinclined portions the slide blocks will be shifted in and out of engagement with the slide bars. Means are provided for holding the slide bars 122 and 123 against free movement which is here shown as comprising spring pressed detents 145 and 146 engageable with notches 147 and 148 formed in the slide bars.

As a means for enabling positioning of the valve 0 at either of two intermediate positions independent of the positioning of said valve afforded by the spring pressed detent 145, the outer periphery of the valve 0 is formed with a pair of sockets 149 and 150 respectively, which are adapted to be engaged by a spring pressed-detent 151.

The valve Q is mounted on a rock-shaft 152 fitted with an arm 153 which connects through a link 154 with a foot operated lever 155 and the valve R is mounted on a rock-shaft 156 fitted with an arm 157, connecting through a link 158 with a foot operated lever 159; the levers 155 and 159 corresponding in their arrangement and mode of operation to the ordinary clutch and brake levers, respectively, of motor vehicels now generally in use.

A suitable liquid adapted for the purposes of hydraulic transmission of power is placed in the conduits 95 and 97 and their communicating ducts and passages in the several valves and in the pump and driving units; a filler tube 160 being provided as shown in Figure 32 which tube extends upwardly from a conduit 161 connecting the pair of conduits 9'7 and terminates on a plane above the uppermost portion of the liquid containing elements whereby on delivering liquid to the tube 160 and preliminarily operating the pump and driving units the liquid will flow into and fill the various communications. The tube is closed by a cap 162.

As a means for absorbing shock as may be caused bysuddenly interrupting the fiow of the liquid during operation of the hydraulic transmission an air trap 163 is provided, here shown as located adjacent the filler tube 160, in which entrapped air will act as a cushion in the well known manner.

The mode of operation of the invention is illustrated diagrammatically in Figures 28, 29, 30, 31, 33, 34, and 35, in which the valves 0 and P are each shown as divided into two sections and the several conduits depicted in a fanciful arrangement for the purpose of facilitating comprehension of the functioning of the various parts.

In the operation of the invention, the valves 0, P, Q, and R are normally disposed in the neutral position shown in Figure 28, whereupon on rotation of the pump rotor as by action of the motor K, the transmission liquid will be caused to flow from the outlet ends of the grooves 76 and 77 of the pump through the ports a and c of the casing M, thence through the valve 0 and back to the inlet ends of the grooves 76 and 77 through the,

ports b and d; the valve 0 being then disposed so that the liquid will flow from the' ports a and 0 through the openings 104 and 106 to the interior of the valve and thence through the openings 103 and 107 to the ports b and d.

Rotation of the pump rotor also causes liquid to flow from the outlet ends of the pump grooves 82 and 83 through the ports e and g in the valve casing N into valve P through the openings 114 and 116, thence from the valve P through the openings 111 and 117 back to the inlet ends of the pump grooves 82 and 83 through the ports I and h, respectively. The transmission liquid will thus circulate through the pump grooves under the urge of the blades 78 and 79 which are caused to alternately traverse the pump grooves 76-77 and 82-83 as before described and as particularly shown in Figure 6; the liquid then flowing as indicated by the arrows in Figure 28 by reason of the positioning of the control valves 0 and P, which is effected by disposing the control lever 120,in the neutral position shown in Figures 23 and 26. With the parts thus positioned the pump merely idles and no effect is had on the driving units.

When it is desired to effect initial propulsion of the vehicle or to drive it under a low gear ratio termed low speed the control lever 120 is moved to cause the block 137 then engaged with the slide bar 123 to advance the latter from the position shown in Figure 23 to that shown in Figure 24 thereby efiecting turning of the valve P a short distance from the position shown in Figure 28 to that shown in Figure 29 in which latter position the passage 109 of the valve P will eifect communication between the ports e and m whereby liquid will be impelled from the pump groove 82 by the pump blades 78 and directed through the conduit 85, valves Q and R, and conduits 95 and 96 to the intake ends of the driving units H to drive the rotors I therein by acting on the blades 54 as will be readily understood; the liquid then returning to the pump through the conduits 97 and 98, valves R and Q, conduit 86 and through the port it, openings 113 and 111 and port 1 of the control valve P.

During this operation, the pump blades 78 and 79 in traversing the pump grooves 76, 77, and 83 will merely circulate the liquid in said grooves through the valves 0 and P.

When it is desired to propel the vehicle at second speed the control lever 120 is operated to cause the block 136 then engaged with the slide bar 122 to advance the latter from the position shown in Figure 23 to that shown in Figure 24 and thereby turning the valve 0 independent of the valve P from the position shown in Figure 29 to that shown in Figure 30 whereby the passage 100 of the valve 0 will effect communication between the ports a and i so that liquid will then' be impelled from the pump groove 76 by the blade 78 and directed through the conduit 85 and through the driving units as above described together with the volume of liquid then impelled by the pump from the groove 82; the liquid impelled from the groove 76 being replaced by liquid flowing to the inlet end of said groove through the port 7', openings 102 and 103, and port b. During this operation the liquid in the pump grooves 77 and 83 will be circulated through the valves 0 and P as before described.

When it is desired to propel the vehicle at third speed the operating lever 120 is advanced to another position in which the block 136 is caused to 5 disengage the slide bar 122 and the block 137 caused to reengage and shift the slide bar 123 and thereby advance the valve P another step from the position shown in Figures 29 and 30 to that shown in Figure 31 in which the passage 110 will then be disposed to eiTect communication between the ports g and 0 whereby liquid will be caused to fiow from the outlet end of the pump groove 83 and be directed to the driving units together with the liquid still being directed thereto from the pump grooves 76 and 82; the liquid discharged from the groove 83 being replaced by liquid returning through conduit 86, port 10, valve openings 115 and 117, and port h.

The pump will now be impelling three streams of the liquid, two of which are moved under the urge of the pump blades located in the pump grooves nearest the axis of the pump rotor and the other of which is impelled by the blades traversing one of the pump grooves more remote from the axis of the rotor. During this operation the liquid in the pump groove 77 will be circulated by the blade 79 through the valve 0 as before described.

When it is desired to propel a vehicle at fourth or high speed the operating lever 120 is again advanced to cause the block 137 to ride out of engagement with the slide bar 123 and to cause the block 136 to engage the notch 139 in the slide bar 122 and eiTect movement of the latter another step so as to turn the valve 0 from the position shown in Figures 30 and 31 to the position shown in Figure 33 whereby the passage 101 of the valve 0 will be disposed in communication with the ports 0 and it so that on rotation of the pump rotor liquid will be impelled by the pump blade 79 from the groove 77 through the port c passage 101 and port lc through the conduit 85 and thence to the driving units H. The liquid 1 impelled from the groove 77 will be replaced by liquid returning through the conduit 86 flowing through the port I, openings 105 and 107 and port it to the intake end of the groove 77. The transmission liquid will then be impelled from each of the pump grooves 76, 77,' 82, and 83 through the passages 100 and 101 of the valve 0 and through the passages 109 and 110 of the valve P in one direction through the driving units H thence back to the pump through the interiors of the valves 0 and P.

Reduction of vehicle propelling speeds is effected by shifting the control lever 120 in a direction opposite that just described whereby the valves 0 and P will be turned alternately step by step back through the series of step movements efiected by advance of the control lever, thereby successively cutting out the propelling action of the liquid directed from the pump grooves 77, 83, 76, and 82 in the order named until the valves are disposed in the neutral position shown in Figure 28, in which position the pump will idle as before stated.

When it is desired to efiect reverse movement of the vehicle the control lever 120 is moved rearwardly from the neutral position shown in Figures 23 and 26 thus causing the block 137 then engaged with the notch 140 in the slide bar 123 to efi ct movement of the slide bar 123 in a reverse direction, thereby turning the valve P from the position shown in Figure 28 to that shown in Figure 34 whereby the passage 118 in the valve P will effect communication between the ports 6 and n, whereby liquid impelled by the pump blade 78 traversing the groove 82 will be caused to pass through the port e, passage 118, port n, conduit 86, conduits 97 and 98, and thence through the driving units H in a reverse direction; the liquid then returning to the pump from the driving units through the conduits 95, 96, and 85, thence through the port m, openings 112 and 111 of the valve P, and port f.

In operating the lever 120 to effect reverse of the transmission, the push rod 1'74 is first manually depressed to move the slide block 171 out of the slot 172, to permit movement of the hand lever the required distance rearward of its normal neutral position.

By the provision of the control mechanism shown in Figures 23 to 27, inclusive, together with the construction of the valves 0 and P and the arrangement of the ports and passages therein as set forth an intermediate gear ratio between the third and fourth speeds may be obtained by positioning the valve 0 at a point intermediate the positions shown in Figures 31 and 33 as illustrated in Figure 35 which is accomplished by disposing the operating lever 120 at a point short of the extreme position assumed when the slide bar 122 has been disposed to place the passage 101 of the valve 0 in full register with the ports 0 and k; the valve 0 being then brought to rest with the detent 151 engaging either of the notches 149 and 150 in the valve 0 to hold the latter so that the passage 101 and the opening 106 therein will each open partly to the port 0 and whereby a portion of the liquid impelled by the blade in the pump groove '77 will be by-passed back to the groove -'77 through the openings 106 and 107 of the valve 0 and the other portion of such liquid being directed through the passage 101 to the conduit 85. The amount of liquid by-passed through the openings 106 and 107 is determined by the extent of overlap of the opening 106 on port 0, which by the provision of the two recesses 149 and 150 affords two selective extents of such overlap; the relative volumes of the liquid by-passed and the liquid directed to the conduit 85, being varied according to changing speed and load conditions. The extent of overlap of the opening 106 on port 0 in either of the selective extents of overlap will be greatly less than the communication between the port 0 and the passage 101 so as to afford a restricted communication through port 0 and opening 106. By this arrangement the operator is enabled to finely adapt the propulsive effort to slightly varying grade or load conditions as where the conditions are such that a reduction of gear ratio from high speed is desirable but is such as not to require reduction to the third speed ratio.

For example, where the vehicle is traversing a level or a slight upgrade and being impelled from the motor K under little power the liquid passing from the port 0 will in, following the path of least resistance flow through the passage 101 into the transmission system and return to the pump groove '77 to the valve openings 105 and 107, but on increase of the grade such as to impose greater duty on the motor and a consequent increase of resistance to the flow of the liquid through the passage 101 then a greater portion of the liquid passing from port 0 will be by-passed back to the pump groove 77 through the valve openings 106 and 107. In this manner an automatic change of gear ratio between the third and fourth speeds will be effected. .Wl'iile the passage 101 will now be in communication with openings 106 and 10'? through port e, no bypassing of liquid from grooves 76, 82 and 83 through the path 85', k, 101, c, 106, 105, I, and 86 will ordinarily occur by reason of the resistance afiorded by the restricted communication between port 0 and opening 106 together with the resistance afforded by the full capacity counter flow of liquid from groove '77 of the pump. However, in event back pressures in passage 101 should become great enough to cause flow of the liquid from passage 101 through port 0 and opening 106, such. would indicate the necessity of manual operation to the third or second gear ratio.

Where the vehicle may be operated without effecting application of power to the driving units, as in coasting, the valves 0 and P may be disposed in their normal neutral positions as shown in Figure 28 by positioning the control lever 120 in its normal position, whereby rotation of the vehicle wheels will in effecting rotation of the rotors of the driving units thereon cause the blades of such rotors to circulate the transmission liquid through the several conduits and valves as indicated by the arrows in Figure 28 in conjunction with the circulation afforded by the rotation of the pump. It will be understood in some instances that when the liquid, propulsive effect of the driving units is in excess of that of the pump the speed of travel of the vehicle will be retarded by the position to offer rotation of the pump afforded by its communication with the drive shaft of the engine K, this in effect creating the condition of coasting under compression in the manner common to the operation of internal combustion engine driven vehicles now generally in use.

By the provision of the foot operated valve Q the fiuid transmission between the pump of the driving units may be interrupted at will to permit the vehicle to coast without shifting the control lever 120 to neutral; depression of the foot lever 155 operating to turn the valve Q so as to dispose the partition 91 to close the communication between the pairs of ports 8788 and 92--93, as shown in Figure 37. The passage q of the valve Q will then afford a communication between the ports 8788 whereby the liquid impelled by the pump will be circulated from the conduit 85 through the port 87, passage q, port 88 and conduit 86. The passage 1 of the valve Q will then afford a communication between ports 92 93 whereby liquid then being impelled by the driving units will be permitted to circulate as by passing through the conduits 9'7 and 98, port 93, passage 1, port 92 and conduits 95 and 96, or vice versa. The vehicle may then be moved forward or backward independent of its power plant.

By the provision of the foot operated valve R movement of the vehicle may be retarded, stopped, and prevented by depression of the foot lever 159; depression of the lever operating to turn the valve B so as to position the passages s and t therein either partially or wholly out of communication with the conduits 95, 96, 97, and 98, and whereby the communications between the pump and the driving units may be restricted or completely closed. On turning the valve R to partially close communication therethrough the flow of the liquid to the driving unit from the pump will be restricted thereby offering a resistance to the flow of the liquid through the valve R and thereby causing the return to the pump of at least a portion of the liquid impelled from the latter by such liquid being caused to by-pass across the chamber formed by the enlarged end portion u of the passage t in the valve R, which chamber will then eifect' communication between the ports 92 and 93.

The propulsive action of the pump on the driving units will thereby be diminished and momentum of the vehicle will be retarded by reason of the driving units then acting to impel the liquid and circulate same between the driving units and the brake R; such circulated liquid passing through the partly open passages s and 1. through the chamber u and under a resistance which will be varied according to the extent of opening of the passages s and t. On depression of the foot lever 159 sufiiciently to turn the valve R such distance as to efiect complete closing of the passages s and 't' as shown in Figure 36 all the liquid impelled by the pump will be returned to the latter through the chamber u thus placing the pump out of operative connection with the driving units. At the same time circulation of the liquid by the driving units will be inhibited, thus blocking rotation of the rotors of the driving units and thereby effecting stopping of rotation of the vehicle wheels and holding the latter against rotation. In event of sudden operation of the valve R to close the passages s and t the air trap 163 which is located between the driving units and the valve R in the return conduits 97 will act to absorb the initial shock occasioned by sudden blocking of the circulation of the liquid by the driving units.

It will be seen from the foregoing that I have provided a means for effecting hydraulic propulsion of a motor vehicle in which the propulsion of the vehicle may be controlled in a manner similar to the control of the ordinary mechanical drive of motor vehicles now generally in use, that is, through the medium of a hand operated change speed control lever, a foot operated lever for throwing the power transmission out of operative connection with the vehicle wheels, and a foot operated lever for eifecting a braking action, with the exception, however, that the hand operated control lever is shifted only in a rectilinear path of travel.

While I have shown and described a specific embodiment of the invention I do not limit myself to the exact details of construction or to the precise arrangement shown but may employ such changes and modifications in the parts and the arrangements thereof as occasion may require coming within the meaning and scope of the appended claims.

I claim:

1. In a motor vehicle having traction wheels and a motor, hydraulically operated driving units on said traction wheels, a rotary pump driven by said motor, said pump including a plurality of pairs of pump elements with one of the pump elements of each pair of greater capacity than the other, hydraulic transmission connections between said pump and driving units including liquid containing conduits leading to and from said driving units and communicating with said pump, a hand operated lever, valve means controlled by said lever for placing one or more of said pump elements in operative relation to said units through said connections to effect various change speed ratios in the hydraulic transmission between said pump and driving units, foot operated means for placing the pump in an out of operative relation to said driving units, and foot operated means for restricting and stopping hydraulic transmission to said driving units.

2. In a motor vehicle having traction wheels and a motor, a rotary pump, said pump being formed with a plurality of pairs of separate pump grooves each of which has an inlet end and an outlet end, one of said pump grooves of each pair being of greater capacity than the other, a rotor included in said pump, means for driving said rotor from said motor, a plurality of blades carried by said rotor arranged to traverse said grooves, liquid pressure operated driving units on said traction wheels, hydraulic transmission connections between said pump and said driving units including liquid containing conduits leading to and from said driving units and eommunicating with the inlet and outlet ends of said pump grooves, a control lever, means for establishing and disestablishing communication between the inlet and outlet ends of said pump grooves and said driving units through said conduits, and means for effecting operative connection between said control lever and said last named means.

3. In a motor vehicle having traction wheels and a motor, liquid pressure operated driving units on said traction wheels, a pump including a housing having a plurality of pairs of pump grooves, one of the grooves of each pair being of greater capacity than the other, a rotor in said housing, means for driving said rotor from said motor, a plurality of blades carried by said rotor arranged to traverse said grooves, said grooves having inlet and outlet ends opening through the pump housing, liquid containing conduits con necting said valve openings to said driving units, a control lever, means for eiiecting operative connection between said control lever and said valve means, and valve means for effecting communication between one or more of said pump grooves and. said conduits progressively as said lever is moved in one direction and to successively close said communication on retrograde movement of said lever.

4'. In a motor vehicle having transmission wheels and a motor, a pump housing formed with two pair of pump grooves having inlet and outlet ends opening through said housing, a rotor within said housing, means for driving said rotor from said motor, blades on said rotor arranged to traverse said grooves, hydraulically operated driving units on said traction wheels, liquid containing conduits leading from said driving units to said pump housing, a pair of valves carried by said pump housing for controlling communication between said pump grooves and said conduits, one of said valves being associated with one pair of the pump grooves and the other with the other pair of pump grooves, said valves including means for effecting communication between the inlet and outlet ends of said grooves when said valves are in a neutral position and at the same time close communication between said grooves and said conduits, means included in each of said valves for placing one or more of the grooves associated therewith in and out of communication with said conduits when said valves are turned forward and back, a control lever and means for alternately operatively connecting said control lever to said valves.

5. In a motor vehicle having transmission wheels and a motor, a pump housing formed with two pair of pump grooves having inlet and outlet ends opening through said housing, a rotor within said housing, means for driving said rotor from said motor, blades on said rotor arranged to traverse said grooves, hydraulically operated driving units on said traction wheels, liquid containing conduits leading from said driving units to said pump housing, a pair of valves carried by said pump housing for controlling communication between said pump grooves and said conduits, one of said valves being associated with one pair of the pump grooves and the other with the other pair of pump grooves, said valves including means for effecting communication between the inlet and outlet ends of said grooves when said valves are in a neutral position and at the same time close communication between said grooves and said'conduits, means included in each of said valves for placing either one or both of the grooves associated therewith in and out of communication with said conduits when said valves are turned forward and back, a control lever, means for alternately operatively connecting said control lever tosaid valves, and means included in one of said valves for effecting reversal of the direction of flow of liquid through said conduits.

6. In a motor vehicle having traction wheels and a motor, hydraulically operated driving units on said traction wheels, a pump including a rotor, a housing enclosing said rotor formed with a series of pump grooves including a pair of grooves facing each of the opposite sides of said rotor, each of said grooves having inlet and outlet ends, a series of blades carried by said rotor arranged to traverse said grooves as said rotor revolves, means for driving said rotor from said motor, a pair of valves, one of said valves controlling the inlets and outlets of the pair of grooves on one side of said rotor and the other valve controlling the inlets and outlets of the pair of grooves on the otherside of said rotor, said valves being adapted when in a neutral po sition to effect communication between the respective ends of said grooves whereby on rotation of said rotor the transmission liquid will be circulated through said grooves and valves, hydraulic transmission connections between said pump and driving units, means included in said valves whereby on disposing said valves in various positions communication will be effected between said conneetions and one or more of said giooves, and manually operated means for effecting alternate positioning of said valves independent of each other.

EARL E. ADAMS. 

